1. Field of the Invention
The invention relates generally to article conveying apparatus, and more particularly to mechanisms for transferring articles between transversely oriented conveyor belts or chains.
2. Reference to Prior Art
Conveying equipment is used in various manufacturing, treatment and other processes for transporting articles. Known conveying equipment includes conveyor chains that are constructed of chain links or modules interconnected by chain pins and that are supported on conveyor frames which define a path of travel for the conveyed articles.
When it is desirable to convey articles along a nonlinear path, it is known to employ side-flexing conveyor chains. Examples of chain links used in side-flexing conveyor chains are provided in U.S. Pat. Nos. 4,893,709 and 4,436,200. Where wider conveying surfaces or higher load carrying capacities are desired, straight-running conveyor chains are often preferred over side-flexing conveyor chains. Examples of chain links used in straight-running conveyor chains are provided in U.S. Pat. Nos. 5,215,185, 5,125,504, 4,858,753, Des. 270,201 and Des. 270,202.
To form a nonlinear conveyor path with straight-running conveyor chains, those chains are arranged transversely to one another and an article transfer mechanism is provided at the intersection to transfer articles between the conveyor chains. In applications where the conveyed articles are not susceptible to tipping and are large enough so as not to fall through the gap between transversely oriented conveyor chains, the transfer mechanism can include only guide rails to redirect the path of the articles. For example, short articles with large "footprints" are sometimes conveyed between perpendicularly oriented small-pitch conveyor chains (i.e., having pitches of less than about one inch) without the need for structure to prevent the articles from falling through the gap between the conveyor chains. In other applications, mechanisms such as static transfer plates and transfer assist conveyor chains are used in conjunction with the guide rails to transfer articles between the conveyor chains.
An example of a conveying apparatus employing, guide rails, a static transfer plate, and a narrow-width transfer assist conveyor chain at a 90 degree turn or "butt corner" between transversely oriented upstream and downstream conveyors is illustrated in U.S. Pat. No. 5,167,319. In that patent, the transfer plate extends along side the upstream conveyor in a gap between the upstream and downstream conveyors. The transfer assist chain is arranged along side the downstream conveyor at the butt corner to fill the transition area defined by the guide rails. In other arrangements the transfer assist chain could also be arranged along side OF the upstream conveyor.